Process of making vegetable glue



, vegetable 1 5 UNITED STATES PATENT OFFICE.

JAMES GQIB. PERKINS AND JULIUS B. B. sTRYKER, or LANSDALE, PENNSYLVAN A,

ASSIGNORS 'ro PERKINs GLUE COMPANY, A CORPORATION or PENNSYLVANIA.

PROCESS OF MAKING VEGETABLE GLUE.

misses.

No Drawing.

To all whom it may concern:

Be-it known that we, JAMES G. B. PER- rims and J ULIUS B. B. STRYKER, citizens of the United States, and residents of Lansdale, in the county of Montgomery and State of Pennsylvania, have invented certain new and useful Improvements in Processes of Making. Vegetable Glue, of which the following is a specification.

Our invention relates to improvements in processes of making vegetable glue. More particularly, the inventlon' relates to processes of making 'a substantially neutral glue having substantially the qualities 0 animal glue for gluing up veneers and the like.

In U. S. Reissue Letters Patent No. 13436,

4 dated July 2,1913, and in U. S. Letters Patent Nos. 1,020,656, 1,078,691, 1,078,692 and 1,200,488, there are making vegetable glue by dissolving a starchy carbohydrate with caustic alkali,

such as caustic soda, the resulting glue being markedly alkaline. Even if the percentage of caustic alkali be reduced to about 3%,

based on the dry weight of the starch and heat be used to aid the solution of the starch,

.the resulting glue is sufficiently alkaline so that when applied to very thin veneers, it will cause a discoloration of the wood veneer, which discoloration may appear on the opposite side of the wood layer from that on which the glue is applied. In many cases this discoloration is not a serious disadvantage, and with the thicker veneers it is not objectionable or does not appear at all. With certain kinds of wood and in certain cases, especially where very thin layers of wood are being glued together, this discoloration or stainlng may be a detriment, which it is desirable to avoid.

The main object of the present invention is to provide a vegetable glue having substantially the properties of the glue described in saidU. S. Letters Patent, but which is so made or treated that this discoloration or stainin is avoided. It is also desirable to provide a vegetable glue for this purpose which is somewhat more fluid than that hitherto in' use. Further objects, features andadvantages will more clearly appear from detailed description given below.

In producing/the new glue, we take a suitable starchy carbohydrate, preferably the glue base resulting from the preliminary disclosed methods of- Specification of Letters Patent. Patented lay 17, 1921,

Application filed September 26, 1917. Serial No. 193,240.

treatment described in either of said U. vS.

Letters Patent. However, certain starches appear on the market which require no preliminary treatment, and these may be used,

8% by weight of caustic soda, the caustic soda being added in the form of a 33% solution. The starch is first thoroughly mixed with thewater and then the caustic soda solution adde'd gradually with continual stirring, until the batch is transformed from a mixture of suspended starch in water to a homogeneous colloidal solution of starch, alkali and water, having substantially the properties of good animal glue for gluing up hi h grade wood veneers, as described in said etters Patent. The resulting glue, although thick and viscous, is capable of flowing through pipes 2 inches in diameter, is capable of being spread by glue applying machinery and has substantially the adhesive qualities of animal glue for this class of work.

To prevent this glue from discoloring and stainingthe wood, as above described, we add thereto a neutralizing agent after the alkali has acted upon .the starch so as to make the glue substantially neutral. While various neutralizing agents have been suggested, we have found that certain ammonia salts have distinct advantages over certain other neutralizing agents, and we prefer ammonium sulfate or ammonium chlorid. In selecting the neutralizing agent and applying the same, we believe it to be imporcreases the degree of dissociation and therefore decreases the flocculatingv action of the sodium salts produced, and by reason of its gradual, progressive and partial elimination, serves to avoid the sudden change of electrostatic condition in the colloidal mass that might result in fiocculating the starchy carbohydrate. While we believe that the ammonia is largely if gradually eliminated from the glue, a certain amount of it seems tolinger in the glue for a considerable time as free alkali, which we believe has the i For the purposes of the invention, therefore,

. is preferable to add the neutralizing agent action of preventing fiocculation'of the glue above referred to, but which does not act to cause staining or dlscoloration of the wood.

the glue is substantially neutral in the sense ofnot staining the wood. We prefer to add the ammonium salt to the glue in the form of a fine powder'in sufiicient quantity to substantially neutralize the glue. in that the caustic alkali is substantlally neutralized- However these ammonia salts may be added in the form of a solution. In either case, it

while the glue is still hot or warm and in- ;about 3% or less of caustic soda.

of caustic deed, we prefer to apply the glue to the wood or other articles beingqoined while it is still warm, especially if made up with The amount of neutralizing agent required may be easily calculated from the amount of alkali used in making the starch glue solu-' tion. While these ammonia salts aresubstantially neutral they act-in asense like an acid in neutralizing the caustic alkali in the glue, combining with the caustic to produce non-caustic salts or bases-which'are eliminated: from the liquid phase by reason of their being, volatile or being inert precipitates.

The neutralizing agent should be thoroughlystirred in so that it is brought into *intlmatejmixture with all parts'of the glue.

We also lfind it advantageous to add with the dry powder neutralizing agent about an equal weight of silicious material, such as, finely ground feldspar, quartz or silica. In-

stead of caustic soda for dissolving the starch, other alkaline compounds may be used. Preferably, lessthan 12% by weight alkali is used in dissolving the starch.

VVhile we prefer to heat the mixture dur ing the dissolving of the starch, thetemperature being carefully kept considerably perature, as described in Perkins below 17 5 F., yet if more than 3% of caustic alkali is used, as, for example, 8%, the solution of the starch may be brought about without heating the batch. By carefully regulating the heat, even less than 3% of caustic alkali may be used. If heat is used,

-it should be carefully regulated to prevent local overcooking of the starch, or overcooking by long continued relatively'high temapplica- 26, 1913,

tion, Serial No. 808739,.filed Dec.

.Dec. 25,

now Patent No. 1,251,275 issued 1917.

If, on standing a considerable time, the glue thickens up, so that it is too viscous and does not flow readily enough, it may in most cases be brought back to proper condition by heating it up to 130-140 F. and thoroughly stirring it. 7 u

While the amount of water used in the process may be varied somewhat, we preferably use 2% to 2;} parts of water by Weight, based on the dry. starch base used. The neu-" tral neutralizing agent when added-should be thoroughly stirred in, so that all parts of the batch will have an opportuntiy to be acted upon thereby.- The addition of the silicious filler seems to increase the adhesive strength of the glue, or prevent the adhesive strength of the glue from being materially decreased. It is, of course, not necessary that the neutral glue be used for joining layers of wood, asit may be found advantageous for-joining fabric to wood and for. joining other articles, but by the method described the glueis rendered substantially neutral without materially decreasing its strength or spreadability or materially affooting its essential properties for furniture veneering and the like, 5

H While, ;'e have described our improvements in great detail and have given certain examples, we do not desire to be limited thereto, since many changes may be made.

(and other reagents used, as will be understood by those-skilled inthe' art. It is de-' siredto cover all the modificationscoming within the language of the appended claims.

2. The process of making vegetable glue which consists in dissolving a starchy carbohydrate with caustic alkali and about 3 parts or'less by weight of water and heat below 1'75" F the carbohydrate being such that the resulting alkaline solution has substantially the properties of animal glue for -gluing up high grade veneers, and then substantiallyneutralizing the glue with ammonium chlorid without materially decreasing its strength or spreadability.-

3. The process of making vegetable glue which consists in dissolving a starchy carbohydrate with caustic alkali and about 3 parts or less by weight of water and heat below 175-F., the carbohydrate being such that the resulting alkaline solution has subv ing'its strength or stantially the properties of animal glue for gluing up high grade veneers, adding an ammonia salt while still warmto substantially neutralize the glue.

4. The process of making vegetable glue which consists in dissolving a' starchy carbohydrate with caustic alkali and. about 3 parts or less by weight of water and heat below 175 F., the carbohydrate being such that the resulting alkaline solution has substantially the properties of animal glue for gluing up high grade veneers, and adding a salt of ammonia in dry powdered form to substantially neutralize the glue .without materially decreasing its strength or spreadability.

5. The process which consists in dissolving ,a starchy-carbohydrate with caustic alkali and about 3 arts or less by weight of water and heat below 175 F., the carbohydrate being such that the resulting alkaline solution has substantially the properties of animal glue for gluing up high grade veneers, and then adding an ammonia salt to substantially neutralize the glue, and a siliciousfiller.

6, The process of making vegetable glue which consists in dissolving a starchycarbohydrate with caustic alkali and Water,

the carbohydrate being such that the resulting alkaline solution has substantially the properties of animal glue for gluing up high grade veneers, and substantially neutralizing the glue with an ammonia salt without materially decreasing its strength or spreadability.

7. The process of'making vegetable glue which consists in dissolving a v bohydrate with water and an alkaline compound, the carbohydrate being such that the resulting solution is a thick viscous alkaline mass capable of flowing through pipes two inches in diameter, and of being spread by glue applying machinery and of adhesively securing layers of wood together, and adding an ammonia salt thereto to substantially neutralize the glue without materially decreasing its strength or spreadability.

8. The process of making vegetable glue which consists in dissolvinga starchy carbohydrate with about 3 parts or less by weight of water and an alkaline compound, the carbohydrate being such that the resulting solution is a thick viscous alkaline mass capa-. ble of flowing through pipes two inches in diameter, and of being spread by glue applying machinery and of adhesively securing layers of wood together, and adding an ammonia salt thereto to substantially neutralize the glue without materially decreasspreadability. I

9. The process of making vegetable glue which consists in dissolvinga starchy carbohydrate with caustic alkali and water, the carbohydrate and proportions being such and thenv of makingvegetable glue starchy car-- that the resulting alkaline glue solution has substantially the properties of animal glue for gluing up veneers, and substantially neutralizing the glue with a substantially neutral salt without materially decreasing lts strength .or spreadability, sa d salt combin-- ing with the caustic to produce a non-caustlc salt or base which is eliminated from the liquid phase-by reasoniof its being-volatile or an inert precipitate. a Y

10. The process of makingvegetableglue which consists indissolving astarchy carbo hydrate base with Water and an alkaline compound, the carbohydrate and proportions being such that the resulting alkaline.

glue solution has substantiallythe adhesive properties of animal glue for gluing up high-grade wood veneers and is viscous but capable of being spread by glue-applying machinery, and substantially neutralizing the glue with a substantially neutral material without materially decreasing its strength or. spreadability,. said neutral ma terial combining with the alkaline compound to produce a non-caustic salt or base which is eliminated from the liquid phase by reason of its being volatile or an inert precipitate.

11. The process of making vegetable glue which consists in dissolving a starchy carbohydrate base with an alkaline compound and about 3 parts or less by weight of] water, the carbohydrate being such that the resulting alkaline glue has substantially the adhesive properties of animal glue for gluing up wood veneers and is'viscous but capa ble of flowing through pipes two inches in diameter and of being spread by glue-applying machinery, and substantially neutralizing the glue with a substantially neutral compound without materially decreasing its strength or spreadability, said compound combining with the alkaline compound to produce a non-caustic salt or base which is eliminated from the liquid phase by reason of its being volatile or an inert precipitate.

12. The process of making vegetable glue which consists in dissolving starch with caustic alkali in about 3 parts or less by weight of water, the condition of the starch being such that the resulting alkaline glue solution has substantially the properties of animal glue for gluing up veneers, and substantially neutralizing the glue with a salt which combines with'the caustic to produce therewith non-caustic products without materially decreasing the strength .or spreadability of the glue.

Signed at Lansdale' in the county of Montgomery and State of Pennsylvania this 22nd day of September, A. D. 1917.

' JAMES G. B. PERKINS.

. JULIUS B. B. STRYKE'R.

Witnesses: EARLY L. GILBERT, 11 E. Moons. 

